实验分析疲劳累计损伤分段函数表示法的合理性

Experimental Analysis on Rationality of Piecewise Function Notation for Cumulative Fatigue Damages

加工带有半圆形缺口的平板试件,采用应变片对材料局部进行应变监测,通过轴向高周疲劳试验,研究了缺陷试件弹性模量损伤特性。结果表明:直至缺陷根部应力集中位置出现裂纹前弹性模量并无明显变化。这一结论与光滑试件所得结论存在差异,对造成差异原因进行简单分析,最终得到疲劳损伤过程存在明显阶段性的结论,为疲劳损伤历程的分段函数表示提供了实验参考。

Flat test pieces with a semicircular notch were processed, and the strain gage was employed to mo- nitor local material; through axial high cycle fatigue tests, the damage characteristics of defected specimen＇ s elastic modulus were studied. Results show that elastic modulus doesn＇t change obviously before the position of stress concentration of defective root becomes cracking, and this conclusion conflicts with that from smooth specimen. Analyzing the variance reason shows that staged fatigue damage exists obviously, this provides refer-ence for the experiment on piecewise function notion of the fatigue damage process.